Abstract: Bispecific binding proteins that bind IL-1? or IL-1R and a checkpoint protein are provided, together with methods of making the proteins. The checkpoint protein may be PD-1 or PD-L1. The binding proteins may have immunoglobulin-like structures that contain human Fab or scFv domains. A novel bispecific antibody format is provided. Methods of making the binding proteins are provided, together with pharmaceutical compositions containing the proteins. The binding proteins and pharmaceutical compositions may be used for treating or preventing diseases such as cancer.